Foot and cutting attachment for hemstitching machines



July 25, 1933 E. PRAZAK l 1,920,105

FOOT AND CUTTING ATTACHMENT FOR HEMSTITCHING MACHINES Filed June 4, 1930 2 Sheets-Sheet' l INVENToR wlTNEssx-:s

ATTORNEYS July 25, 1933. E. PRAZAK 1,920,105

FOOT AND CUTTING ATTACHMENT FOR HEMSTITCHING MACHINES Filed June 4, 1930 2 Sheets-Sheet 2 Patented July 25, 1933 l UNITED STATES PATENT- oFFlcE EMIL PRAZAK, OEELTZAEETH, NEW JERSEY FooT ANDCUTTING ATTACHMENT Eon HEMsTIToHING MACHINES Application inea June 4,' 1930. seriaino. 459,195.

stitchinginachines which `is `provided with cutting-blades wherein the throat plate is provided'with a guide and 'a slot positioned nearV the needles so thatfthe hemstitching may be cut at the proper'time to secure a 0 desired picot effect on each edge'of Vthe cnt goods. y

A still further object of the present invention is to provide an improved form of foot for a hemstitching machine which is particularly adapted to allow ample ymovement of the cutting knife and piercersv and vneedles, so that the parts may "function in a close group. l

In the accompanying drawings- "Figure 1 is a fragmentary side view of a hemstitching machine illustrating lan`at-` tachment embodying the invention vapplied thereto, certain parts being broken away for better illustrating thestructure; 1

l Figure 2 is a top plan view of the presser foot shown in Figure 1; l

`Figure 3 is a front view ofA tliefpresser foot shown in Figure l;

Figure 4 is a top plan view of the vthroat plate and feeder shown in Figure 1;

holder shown in Figure 1, together with a cutting bladeqor knife kand itsl supporting 3fm; L Figure 6 is a detailed perspective view of vfoot 'as' the machine functions.

needleiopening in the throat yFigure 5 is a frontA view of the piercerof fabric vshowing how the stitching is applied and then cut to. form a picot on the two cut edges, the knifefand part of the piercer being shown in connection therewith.

Referring to the accompanying ldrawings by numerals, 1 indicates a conventional type of hemstitching machine, provided with the usual reciprocating bar 2 carrying at its lower end an auxiliary piercer 3 and a pair.

of needles 4. The auxiliary piercer 3 and 6o the needles 4 are movable through ya presser Coacting with the presser foot 5 is a Vfeeder or feed dog 6 formed in a conventional way ywith slot'7 which extends to a point near the plate rand is usual for a device of this'kind.

' As shown in Figure 1, the guide S is pro-y vided with a long foot 9 carrying twoscrews 10. It will be. noted in this structure that 70 the entire supportof the guide 8 is on lthe side opposite the slot 7. A piercer bar 11 forms lpart of the machine 1 and carries a specially lformed piercer holder 12, said holdercarrying the piercer 13 located between the needles 4 and adapted to spread the stitches madeby these needles. The function of the piercer 13 is usual and therefore forms no part of the present invention except :in combination. The inventionis directed to the various parts and the attachment which 'are adapted to assist in forming the picot edging 14, as shown on a piece of fabric 15 in Figure-8. AfterJeach time the Y needles 4 function the piercer 13 spreads the cloth or fabric, and immediately thereafter the knife lor cutting blade 16 severs the threads.

` From Figure 5 it will be noted that the piercer holder 12 has a'laterally extending 9U arm 17 having a countersunk 18 anda slot 19. Also arm 17 is provided with a longitudinally arranged groove 20 forreceiving the bead 21 of the knife army22. Knife arm 22 is provided with va socket 23 for receiving the -end 24 of 'knife 16,-'whereby the screw 25 may rigidly clamp theknife to arm A22.

Arm 22 isprovided with a tl'ireaded'aper-A ture 26 for receiving the screw 27 which extends through' slot 19, whereby arm 22 100 Y ac ' Ydivided intotwo parts and yis formedwitli a slot 32 through which the ;knife 16'A moves be adjusted longitudinally of arm 17 j and thereby adjust theposition of knife 16.A

In order that armV 22 may be readily grasped by the thumb Vand fingers a roughened section 28 is provided, said roughened section consisting of grooves cut into the arm.'k A screw, 29 is threaded into arm 22 and extendstlirough the slot 30cin the abutmentor stop 31." After theknife 16 has been once properly adjusted and lscrew 27 tightened the abutment 31 is moved until it presses tightly against the piercer holder 12, as shown in Figure 5, and then screw 29 is tightened. After this has been once done the abutment is usually'left in its adjusted position and screw 27 removed when itis desiredto remove the arm 22for replacing a blade 16er for anyother purpose. j When it is desired tol replace the arm 22 the saine may be merely held in approximately correct povsition so that the screw 27l may be inserted.VV

Beforethis screw is tightened yarin 22 is slid over to the right in Figure 5 untilth'e abutment 3l presses tightly againstthe holder 12,andrthen screw 27 is tightened. Inathis way the parts maybe quickly and accurately adjustedfso 'that the blade 16y will properly extend through theV ,slotl 7 operation of the'machine.

As shown in Figures 2 and 3footi-5dis c as the machine functions. As shown in Figotlie'rwiseto the block 34 and also to the l tegral with block 34 and' is connected theref ure 3the foot section 5'; is provided fwith an upwardly extending standard 33 Vmerging into a block 34 carrying a'V pin 35 on whichv the standard 36A slides,l,said standard beingintegral with the foot section 5 and having a slot 37 therein for accommodating Vthis pin.V A set 'screw 38. acts to lockthe pin against movement vin the extension 39of block 34. Block `34 is provided with an aperture 40 'for accommodatingV a bar 41 which is clamped to `the' block by a'set screw 42. `VArm 36 extending from4 block34lvhas4 `a.,laterally extending section 43 provided with an aperture throughwhich bar'41 extends, and a set screw `44 clamps extension 43 to the'bar 41. i i i i 1 A small plate 45 issecuredby a screw or auxiliary block 34', which is rpreferably in-` with by the auxiliary standard 36 `AuxiliV ary block 34`is providedwith anaperture through which the bar` 41: extends. The

block 34 is provided, with al slot at the rear so that itm-ay be clamped to bai' 41by a` suitable Aclamping screw 46.*; Iii-this .way

the two parts are held together so `as to function as a single structure, and .at the same:-

tiine presenta slot32 for knife-1G, fByproviding .the narrow bar45 ample space i is left :for Vthe arm 22 and associatedparts` to function as the knife is moved up and down.

.during the In operation the auxiliary piercer 3 upon descent ofthe bar 2 cuts a hole, as indicated by the numeral 47 in FigureS, in the fabric As this perforation is fed under the ncedlesitsy edges are stitched, as indicated at 43, andthe threads are pushed apart byA the piercer 13 so that the heinstitching includesja vseries of perforation's' vstitched at their edges'and a series of cross threads, such as'49, between the perforations. It is the function-ofthe knife' 16 upon its descent to cut these threads and thereby simultaneously foi-m two picotedges, such as 14 as shown in Figure 8. i

`What I claim" is;

j 1. The combination with a hemstitcliing machine including a presser foot and a piercer bar, of a piercer holder carried by said bar and formed with a supporting arm, said Asupporting arm being formed with a vlongitudinally positioned groove in one side land a rslot extending through the arm, said slot-being spaced :from said groove, a knife` movable through said presser foot, aknife arm carrying saidknife, said knife arm bheing formed witha bead slidably fitting ni said groove, a threaded aperture spaced from i-saidjbead, and a' clamping screw extending through the slot', in said supporting arm into said threadedaperture for. ustrocating `piercerbar and a holder bar, cfa

supporting arm carried by` the holder bar, a knife movable through said presser foot, a knife arm adapted towbe secured to said supporting arm,` means for securing" said knife .to said" knife arm, means for adjustably securing the knifearm to said supportingann, and an adjustable stop carriedby said knifev arm adapted to limit the adjustnient of saidknife arm. in one direction.,

j In an attachment `for 'a hemstitching machine, a piercer holder having a laterally extending `piercer arm, a knife, al-knifearm mounted on said piercer arm Vand adjustable longitudinally thereof, said knife arm being formed with a socket in one end adapted to receive one Vendof said kiiife,'and`a threaded screw-receiving opening to receive a supporting screw, and a i screw extending through one end of said knife into said knife arm acting to clamp the knife in saidsocket and a stop member adjustably mounted on said knife arm for limiting the adjustable movement ofthe-knife arm in one direction.

4. In an attachment for a hemstitchiiigV machine, the combination with a piercer holder having a groove in one face, of a knife, a knife arm having a longitudinally positioned bead adapted to slidingly fit into said groove for preventing rotationof said knife arm. in respect to said holder, means for rigidly securing the knife to said knife arm, an adjustable stop carried by the knife arm coacting with one end'of said holderfor limiting the movement of the knife arm 1n one d1rect1on and a clamping `screw for clamping said knife arm and said holdertogether, said screw When functioning causing said bead in turn to function.

5. In an` attachment for -a henistitching machine, a knife arm, a knife removably secured to one end of said arm, said arm beingl ened portion.

` EMIL PRAZAK. 

